Automobile engines can generate a significant amount of heat during operation. Conventional cooling systems for engines include water pumps that circulate water or other coolants throughout the engine. Mechanical pumps (e.g., belt, chain or gear pumps) are popularly used in internal combustion engines. The pumps are driven by the rotational force of the engine crank shaft. Consequently, it is difficult to adjust or control the pump flow rate without adjusting the engine speed.
Additionally, there can be substantial parasitic losses when using mechanical pumps to cool the engine. Parasitic loss reductions can improve the fuel economy of internal combustion engine vehicles. Electric water pumps can be more efficient than mechanical pumps. For example, electric pumps can be controlled to reduce pump performance in instances where there is less demand on the cooling system. Flow requirements of larger engines and limited passage ways, however, can make the use of electric pumps prohibitively expensive, large and heavy.
Lastly, packaging the cooling system for an engine can be limited by other components of the vehicle. With larger engines requiring higher flow and pressure demands, larger pumps significantly increase the required packaging space.
Therefore, it is advantageous to reduce parasitic losses due to pumping coolant throughout the vehicle cooling system due to mechanically driven water pumps. It is also advantageous to provide a cooling system that can be packaged in smaller spaces.